Geological Map of the Rocca Busambra-Corleone region (western Sicily, Italy): explanatory notes

ABSTRACT

The geology of the Rocca Busambra-Corleone region, in central-western Sicily, is relevant to the understanding of the central sectorof the Maghrebian-Sicilian fold-and-thrust belt.

In the investigated area Mesozoic shallow- and deep-water carbo -nate deposits pertaining respectively to the Trapanese and the Sica -nian successions, and a thick Oligo-Miocene numidian flysch body,crop out. Minor outcrops of Cretaceous-Palaeogene Sicilide complexand syn-orogenic deposits of the Late Serravallian-Early MessinianCastellana Sicula and Terravecchia formations are also present.

A structural analysis reveals complex tectonic relationshipsbetween the Trapanese carbonate platform tectonic unit (the RoccaBusambra carbonate ridge) and the overthrusting Sicanian deep-water carbonate (Corleone-Barracù) and numidian flysch tectonicunits, outcropping around the carbonate ridge.

In this tectonic frame Rocca Busambra is a 15 km long, E-W-trending large antiform, slightly rotated to the NW-SE on its easternlimb (Pizzo Marabito). The unit forms a southerly verging ramp struc-ture; it is bound, to the south, by E-W and WNW-ESE striking majorreverse faults and, to the north, by the E-W striking Busambra fault,that is a back-verging reverse fault characterized by right-handedstrike-slip component of movement. The Busambra carbonate plat-form tectonic unit, that appears to have been thrust up to the surface,is reimbricated above the Sicanian deep-water carbonate and numi -dian flysch tectonic units; these, in turn, are redeformed. The lattertectonic event overprinted the original tectonic relationships and tookplace during the Late Pliocene, as evidenced in adjacent regions.

KEY WORDS: Western Sicily, geological survey and map-ping, Mesozoic shallow- and deep-water carbonate suc-cessions, tectono-stratigraphic setting, Meso-Cenozoicdeformational history.

INTRODUCTION

The Rocca Busambra-Corleone region (fig. 1a), lo -cated in the Belice valley between the southern PalermoMountains and the north-western Sicanian Mountains, isa very complex area of the Western Sicily fold-and-thrustbelt (from now on named FTB).

The first detailed study carried out in the region isdue to MASCLE (1979), who compiled a geological map(1:100,000 scale) of the whole Sicanian Mountains region;the related explanatory notes are an important support tothe geological knowledge of the area.

CATALANO & D’ARGENIO (1978; 1982a) and CATALANO& MONTANARI (1979) proposed a tectonic framework ofwestern Sicily with a concise description of the stratigra-phy. These authors distinguished the main structural-stratigraphic units and their geometric relationships.

Several other studies have been carried out to describethe stratigraphy of the area (WENDT, 1963-1971; MASCLE,1973, 1979; MARTIRE et alii, 2002; BASILONE, 2009) and itsstructural setting (ROURE et alii, 1990; LENTINI et alii,1994; AGATE et alii, 1998a; CATALANO et alii, 1998, 2010a, b;NIGRO & RENDA, 1999; 2001; MONACO et alii, 2000). As aconsequence, several and controversial interpretations,concerning both the stratigraphic and the tectonic settingof the Rocca Busambra-Corleone region, grew up.

In spite of the previous and thorough work about thestratigraphy and the tectonics of the study area, nodetailed scaled field mapping has yet been compiled.

Regional studies in the frame of the CARG project inWestern Sicily (Carta Geologica d’Italia, 1:50,000 scale)have led the present Author to collect new field and ana-lytical data with the aim of compiling a detailed geologi-cal map of the Rocca Busambra-Corleone area. The fieldwork carried out at a 1:10,000 scale is assembled andpresented on a base-map at a 1:37,500 scale. The mainresults concerning the geological knowledge of the region,the stratigraphic and structural features are illustrated inthe present explanatory notes.

The present work is an attempt to give detailed fieldmap support to some new insight concerning the struc-tural evolution of the region in the frame of the SicilianFTB. The geology of the area is particularly valuable tothe understanding of the tectono-sedimentary evolutionof the Mesozoic Sicilian continental margin and theCenozoic-Quaternary deformational history (includingthin-skinned and later envelopment thrusting).

GEOLOGICAL FRAMEWORK OF WESTERN SICILY

Western Sicily is a part of the Maghrebian SicilianFTB, a segment of the Alpine collisional belt, recentlydescribed (CATALANO et alii, 2000 and reference therein)as a result of both post-collisional convergence betweenAfrica and Europe and roll-back of the subduction hingeof the Ionian lithosphere (fig. 1b on the frame of the map).

The western Sicilian FTB (fig. 1a) is the result of thepiling up of tectonic units derived from the deformationof distinct ancient paleogeographic domains. The latterwere developed, during the Meso-Cenozoic, in the Siciliansector of the southern Tethyan continental margin(BERNOULLI & JENKINS, 1974; CATALANO & D’ARGENIO,1978; STAMPFLY & BOREL, 2002).

The tectonic edifice is characterized by the occur-rence of three main structural levels (fig. 1b), from thebottom, consisting of: a) imbricated slices of carbonate

(*) Dipartimento di Geologia e Geodesia, Università di Paler-mo, Via Archirafi, 20-22 - 90123 Palermo. [email protected]

Geological Map of the Rocca Busambra-Corleone region(western Sicily, Italy): explanatory notes

LUCA BASILONE (*)

Ital.J.Geosci. (Boll.Soc.Geol.It.), Vol. 130, No. 1 (2011), pp. 42-60, 14 figs., 4 tabs., 1 pl. f.t. (DOI: 10.3301/IJG.2010.17)

platform tectonic units (Panormide, Trapanese and Sac-cense domains); b) a wedge of deep-water carbonatethrust sheets (Imerese and Sicanian units); c) the Sicilidinappes and the numidian flysch units, detached fromtheir substrate. These tectonic units are overlain bywedge-top basins, filled by Miocene-Lower Pleistoceneclastic deposits, evaporites and carbonates.

The tectonic emplacement took place during theMiocene-Early Pleistocene time interval. It is commonlyassumed that a S and ESE verging thrust propagation(CATALANO & D’ARGENIO, 1982a) accompanied by clock-wise rotations (CHANNELL et alii, 1990; OLDOW et alii,1990) and deep-seated thrust planes with strike-slip com-ponent of movements (GHISETTI & VEZZANI, 1984)occurred. The deeper rock successions have been detachedfrom their substrate from these faults, forming axial cul-minations and ramp structures (OLDOW et alii, 1990;CATALANO et alii, 1998, 2010a; AVELLONE et alii, 2010).

MAPPING METHODOLOGIES

Field mapping was carried out using published basemaps (Carta Tecnica Regionale of the Regione Siciliana)at a 1:10,000 scale. Satellite and aerial images were ana-lyzed in order to recognize the main morphostructuralfeatures. The geological map is presented at a scale of1:37,500 in a Transverse Mercator Projection.

Lithostratigraphic criteria and facies analyses wereused to distinguish 22 formations. The detailed reconnais-sance is also supported by paleontologic analyses. The car-bonate deposits were investigated also using petrographicaland sedimentological analyses; the resulting lithofacieswere biostratigraphically calibrated, mostly based on Juras-sic ammonite biozonation (WENDT, 1969), calpionellids bio-zonation (ALLEMAN et alii, 1971), and Cretaceous-Miocenecalcareous plankton biostratigraphy (CARON, 1985; IAC-CARINO, 1985; PERCH-NIELSEN, 1985; FORNACIARI et alii,1996; FORESI et alii, 2001; SPROVIERI et alii, 1996, 2002).

Field mapping was integrated with structural analysesat a map and mesoscopic scale.

Field results, calibrated by seismic profiles interpreta-tion (CATALANO et alii, 1998; 2000), allow us to recognizethe spatial continuity of the rock bodies at depth and thestructural setting of the study region.

THE GEOLOGICAL MAP

The map includes:

a) a northern sector, characterized by the RoccaBusambra carbonate ridge and its western continuation(Rocca Argenteria, Rocca del Drago), a 15 km long E-Woriented complex morphostructure, made of Mesozoic-Miocene shallow-to-pelagic carbonate succession (Tra-panese paleodomain);

b) a south-western sector, around the Corleone town,where the Cretaceous-Miocene carbonate and clasticdeposits, pertaining to the Sicanian deep-water succes-sion, outcrop;

c) an eastern and northernmost sector (Godrano-Ficuzza region), where the Oligo-Miocene numidian flyschdeposits prevail;

d) minor outcrops of Sicilide deposits, are mapped inthe north-westernmost corner;

e) Miocene foredeep clastic rocks, largely outcroppingin the south-western area.

GEOMORPHOLOGIC OUTLINE

The geomorphologic configuration of the studyregion can be summarized in two different landscapetypes, related to the outcropping lithologies and to theprevailing morphogenetic processes.

The carbonate highland landscape (Rocca Busambraridge 1613 m a.s.l.) shows geomorphic forms due to tec-tonics and morphoselection, such as the several palaeo-surfaces, and the wide, structurally controlled, scarps,hundreds of metres high. In the Contrada Giardinello(south of Rocca Busambra ridge on the map), the largeblock movements and the E-W oriented opening trenchesand fractures suggest deep-seated gravitational slope de -formation (AGNESI et alii, 1978). These phenomena origi-nate mass rock movements of more than 500.000.000 m3.The landslides have masked the original tectonic relation-ships between the outcropping tectonic units.

GEOLOGICAL MAP OF THE ROCCA BUSAMBRA-CORLEONE REGION 43

Fig. 1 - a) Structural map of central-western Sicily (modif. fromCATALANO et alii, 2004); b) Regional geoseismic profile (modif. fromCATALANO et alii, 2000), across the central sector of the westernSicily fold and thrust belt, showing the main tectonic features.LEGEND: 1) Panormide carbonate platform tectonic units; 2) Imeresebasin tectonic units; 3) Trapanese-Saccense pelagic platform tectonicunits; 4) Sicanian basin tectonic units; 5) M. Genuardo carbonateplatform-to-basin tectonic unit; 6) Numidian flysch tectonic units;7) Miocene syn-tectonic deposits; 8) Miocene-Pliocene deposits;9) Pleistocene deposits; 10) study area; 11) trace of the regional geo-seismic profile of fig. 1b.

The marly clayey hilly landscape consists of gentlereliefs with low, inclined slopes, where landslide phe-nomena and water processes prevail. The mapped land-slides, mostly due to a rotational creep, are both activeand inactive (no recent movements in the last fewdecades). The largest landslide bodies are more than 2 kmlong and 1 km in length, and some tens of metres thick.Spectacular examples are mapped in the region sited tothe south of Monte Cardellia, where clayey deposits(Cardellia marls), embedded between two limestone levels («Corleone calcarenites» and Amerillo Fm), arerepeatedly mobilized.

Fluvial processes originate several orders of alluvialterraces (mapped along the main rivers) and spectacularerosional canyons in the Corleone town area, where alsolateral spreading phenomena occur.

LITHOSTRATIGRAPHY AND FACIES ANALYSIS

The outcropping lithostratigraphic units (fig. 2 onthe frame of the map) will be described in descendingorder, starting from those pertaining to the highest struc-tural units in the study sector. The description is accom-

panied by some illustrations (figs. 2-9) and summarytables (tabs. 1-4), concerning the main lithostratigraphic,environmental and paleontological features of the forma-tions. The stratigraphic columns presented in figs. 3 and 9show detailed sequences of the Monte Barracù and RoccaBusambra successions. The following paragraphs describethe individual rock units in some detail.

SICILIDE DEPOSITS

The Sicilide terrains, a few tens of metres thick, out-crop, as scattered patches, at Case Bifarera, Cozzo Arcuriand Masseria Nicolosi (northern sector of the map),where the rocks tectonically overlie the numidian flyschdeposits. They include Late Cretaceous varicoloured sili-cified clays, shales and marls of the «varicoloured clays»(AVF on the map) and Middle-Late Eocene white pelagiclimestones (Polizzi Formation, POZ on the map, tab. 1),with intercalations of graded and laminated packstone-wackestone rich in benthic macroforaminifers, pectinids,Corallinacean algae, crinoid and echinoid fragments (tab. 1). The mudstone-wackestone beds show bioturba-tion (ichnofacies with Palaeodictyon isp., Nereites isp.,Helminthoida isp.) and, locally, volcanoclastic layers(Contrada Bifarera).

44 L. BASILONE

Fig. 2 - The numidian flysch lithofacies: a) shales (Portella Colla mb) with iron-manganiferous crusts (Pizzo Candreo); b) hectometres tur-biditic succession of the Geraci Siculo mb (Bosco della Ficuzza); c) massive thick-bedded coarse and well-rounded quartz-conglomerates, alternated with yellow fine-sandstones with parallel and oblique lamination; d) detail of a turbiditic bed: Ta) graded conglomerates, b) chaoticcoarse sandstones, c) sandstones with normal gradation and parallel lamination, d) laminated mudstones and e) greenish clays.

NUMIDIAN FLYSCH DEPOSITS

The numidian flysch formation consists of UpperOligocene-Lower Miocene clays and shales with thick tur-biditic quartz-sandstone and conglomerate intercalations(fig. 2). The unit, more than 800 m-thick, widely outcropsboth in the northern and eastern sector of the map, whereit tectonically overlies the Sicanian rock unit. The terrige-nous wedge lacks of its original Mesozoic-Eocene carbo -nate substrate, found elsewhere. The formation is madeup of two members (tab. 1).

The Portella Colla member (FYN2 on the map) con-sists of 100-200 m-thick brown manganiferous laminatedclays (fig. 1a), locally scaly, with m-thick yellowish silt-stones and fine-graded and laminated quartz-sandstoneintercalations; it outcrops at Nicolosi, Scalilli, Bifarera,Madonna di Tagliavia areas (north-western sector of themap) and at Pizzo Candreo (few metres). Planktonicforaminifers and nannoplankton content suggest a Chat -tian-Lower Aquitanian age.

The Geraci Siculo member (FYN5 on the map) con-sists of an upward thickening turbiditic sequence (fig. 2b).The recognized lithofacies are: a) massive thick-beddedconglomerate (fig. 2c) alternated with yellow-reddishfine-to-coarse planar- and oblique-laminated sandstone.The conglomerate layers, with erosional lower boundaryare coarse and well-rounded quartz grains; b) siliceoussandstones, commonly with erosional lower boundary,and complete turbiditic facies sequences (fig. 2d); mud-supported texture pebbly conglomerate, ten metres-thick,with darkish mudstone intraclasts, are locally inter -

layered. The Geraci Siculo member is well-exposed in theBosco della Ficuzza, Bosco del Cappelliere, Marosa andCozzo Donna Giacoma areas (eastern and southern sector of the map). It is dated as Lower Miocene (basedon planktonic foraminifer and nannofossil biostratigra-phy, tab. 1).

INCERTAE SEDIS DEPOSITS

At Contrada Bicchinello (south of Pizzo Nicolosi), asmall rock body of Eocene breccias and bioclastic pack-stone-grainstone with benthic macroforaminifers (num-mulitids, alveolinids), crustacean and bivalve fragments(Bicchinello limestone, PUN on the map), crops out.These deposits are believed to be the remnants of tectonicslices pertaining to the Prepanormide tectonic units(CATALANO et alii, 2010a and reference therein).

SICANIAN DOMAIN DEPOSITS

The whole Sicanian succession is well exposed atMonte Barracù, immediately to the south of the studyregion (MASCLE, 1979; AGATE et alii, 1998b), as shown bythe detailed stratigraphic column (fig. 3). Its depositionalcharacteristics point to a deep-water Triassic-Miocenepaleodomain. In the study area only some lithostrati-graphic units are mapped (tab. 2):

a) Mufara Formation (MUF on the map). Late Triassic(Carnian) thin-bedded laminated grey mudstone and dark-yellowish marls, with halobids, ammonites, radiolarians,


TABLE 1

Lithostratigraphic characters of the Sicilidi deposits and numidian flysch formation.

Main lithology Environ Fossils content Age

Varicoloured silicized clays, chaotic shales, mudstone and packstone intercalations 20

-50m

Bath

ial p

lain

Planktonic forams (Rotalipora appenninica, R. brotzeni and R. reicheli biozones) and calcareous nannofossils (CC 25-26) A

lbian

-Ce

nom

anian

White pelagic limestones wirh ichnofacies (Palaeodictyon isp., Nereites isp., Helminthoida isp.), graded and laminated packstone intercalations. Volcanoclastic layers (C.da Bifarera)

20-5

0m

Dep

ositi

onal

slope

-to-

basin

Planktonic forams (Hantkenina nuttall, Truncorotaloides rohri, Globigerinatheka semiinvoluta, Turborotalia cerroazulensis s.l. biozones) and calcareous nannofossils (NP 20 biozone). Nummulitids, alveolinids, discocyclinids, pectinids, corallinacean algae, crinoid and echinoid fragments in the resedimented beds M

iddl

e-U

pper

E

ocen

e

Ger

aci S

iculo

mb.

(F

YN

5)

Megabeds of well-cemented quartz turbidite sandstones; pebbly conglomerates, some metres-thick, with darkish mudstone intraclasts, are locally interlayered

300-

700m

Slop

e to

turb

idite

fan

Planktonic forams (Globigerinoides trilobus, Globoquadrina dehiscens dehiscens-Catapsydrax dissimilis biozones), calcareous nannofossils (MNN 1 and MNN2b) and arenaceous foraminifers (Ammodiscus spp., Cyclammina spp., Trochammina spp.)

Aqu

itani

an-B

urdi

galia

n

Porte

lla C

olla

mb.

(F

YN

2) Brown manganesiferous laminated clays, graded and laminated quartz sandstone (FYN2a) intercalations. 10

0-20

0m

Slop

e to

toe-

slope

Planktonic forams (Globorotalia opima opima, Globigerina ciperoensis ciperoensis, Globoquadrina dehiscens dehiscens-Catapsydrax dissimilis biozones) and calcareous nannofossils (NP 24-25, MNN 1b)

Chat

tian-

Low

er

Aqu

itani

anNum

idian

flys

ch F

m.

Varicoloured clays (AVF)

Polizzi Fm. (POZ)

conodonts, palinomorphs, gastropods and rare arenaceousforaminifers. It outcrops, 10-30 m thick, at Masseria Cicio,Masseria del Casale, Puntale l’Ape, Masseria Nicolosi andCozzo Tondo. The beds are strongly folded and faulted;

b) Hybla Formation (HYB on the map). Lower Creta-ceous grey-blackish thin-bedded cherty limestones withradiolarians, sponge spiculae and planktonic foraminifers(fig. 4a), whitish marls rich in belemnites (Duvalia lataBLAINVILLE) and mollusc shells. Coarse-grained pack-stone with Aptychus fragments, are interlayered. The unitis mapped along the Rocca Busambra ridge in the Con-trada Giardinello (south of Pizzo Marabito), where inspite of the strong deformation (folds and faults), it is upto 50 metres thick; its lower boundary does not outcropon the map.

c) Amerillo Fm (AMMa-d on the map, fig. 5). The for-mation is Upper Cretaceous-to-lower Oligocene reddish-to-whitish thin limestones and marly limestones (figs. 5a, b)with planktonic foraminifers (fig. 4b), limestones withichnofacies (fig. 5c) and calcareous turbidites with ma -croforaminifers (fig. 5d and fig. 4c). Carbonate megabrec-

cias (AMMm on the map) occur in beds in the Campa -nian-Lower Maastrichtian interval of the pelagic succes-sion. They are well-cemented sub-rounded cobbles andboulders deriving from the break up of the upper Trias-sic-Jurassic peritidal limestones and pelagic deposits.

The Amerillo Fm, 200 m-thick, outcrops at Portelladel Vento, Piano della Tramontana, Contrada Giardinello,Casale and Pirrello (south-eastern side of the RoccaBusambra ridge), where the lithofacies described aboveare identified and mapped. These deposits, previouslyinterpreted as pertaining to the Trapanese domain(GIUNTA & LIGUORI, 1975; MASCLE, 1979), appear wellcorrelated with the typical Sicanian Amerillo Fm outcrop-ping at Monte Barracù (southern edge of the map).

d) Cardellia marls (RDE on the map). Chattian-LowerAquitanian marls and dark-green marly clays with ironnodules are rich in calcareous plankton; benthic macro-foraminifers (nummulitids and Nephrolepidina spp.) bear-ing turbidite packstone (fig. 4d) are interlayered. Thesebeds, 100-200 m-thick, conformably follow the AmerilloFm. The recently proposed «Cardellia marls» formationoutcrops at Contrada Bifarera (northwestern corner ofthe map, see also MASCLE, 1979), at Contrada Casale andPirrello (southern side of Rocca Busambra), around thetown of Corleone and at Monte Cardellia, where the pro-posed type section (fig. 6) is based on the biostratigraphicstudy of BIOLZI (1985).

e) Corleone calcarenites (CCR on the map). LowerMiocene glauconitic grainstone and packstone with benthicmacroforaminifers (figs. 4e, f), calcareous and quartz-sand-stones and greenish silty marls, unconformably follow. Thelower boundary of the unit is a sharp and erosional uncon-formity surface above the Cardellia marls, as seen along theMonte Cardellia section (see fig. 6). The «Corleone calcaren-ites», 20-80 m-thick, outcrop at Cozzo Zuccarone-CozzoRubino anticline and, with maximum thickness, at MonteCardellia and in the Corleone town, where the Rocca deiMaschi natural section was analyzed and sampled withdetail to propose the type section of the formation. Themeasured succession (fig. 7), 70 metres thick, yellow andgreen in colour due to the occurrence of abundant glau-conite minerals, consists of cyclic alternations of quartz-glauconitic sandstones and bioclastic packstone in dm-thickbeds with green marls. Several lithological intervals can beevidenced due to the composition of the beds and theirerodible features; the succession is organized at least in two3rd order transgressive-regressive cycles.

f) San Cipirello marls (CIP on the map). Upper Ser-ravallian-Lower Tortonian grey and sky-blue clays, clayeymarls and sandy marls with rich planktonic content, 50-150 m-thick. The marls outcrop at Cozzo Zuccarone,Contrada Pirrello, Sant’Ippolito and Vallone del Poggio(Corleone town area), where conformably overlay, with asharp surface, the «Corleone calcarenites».

The lower portion of the Sicanian succession (ScillatoFm, oolitic calcarenites and Prizzi breccias, Barracù radio -larites and Lattimusa, fig. 3) does not outcrop in thestudy region. Seismic profile interpretation and subsur-face data suggest these rocks are presently buried in theregion (CATALANO et alii, 1998; 2004).

TRAPANESE CARBONATE PELAGIC-PLATFORM DEPOSITS

The Rocca Busambra rocks pertain to the Meso-Ceno-zoic Trapanese paleogeographic domain (CATALANO &

46 L. BASILONE

Fig. 3 - Triassic-Miocene deep-water Sicanian stratigraphic succes-sion, measured and sampled along the Monte Barracù natural section.

D’ARGENIO, 1978), where shallow marine and pelagic car-bonate platform deposited progressively. The typical con-densed sedimentation and facies variability of the Juras-sic-Cretaceous deposits have been already investigated(CHRIST, 1960; TAMAJO, 1960; WENDT, 1963-1971;JENKYNS, 1970a; MARTIRE & BERTOK, 2002; BASILONE,2007), as well the tectono-sedimentary features of theJurassic-Cretaceous deposits exposed at the Piano Pilatosector (WENDT, 1971; GIUNTA & LIGUORI, 1975; MASCLE,1973, 1979; GULLO & VITALE, 1986; MARTIRE & MON-TAGNINO, 2002; BERTOK & MARTIRE, 2009).

Tectono-stratigraphic features, such as paleofaults,buttress unconformity relationships, a dense network ofneptunian dykes with several infilling generations andseveral large hiatuses, have been recently discussed asuseful constraints to the palinspastic restoration of theJurassic-to-Miocene tectono-sedimentary evolution of theRocca Busambra (BASILONE, 2009).

The succession starts with: well-exposed Upper Trias-sic-Lower Jurassic carbonate shallow marine depositswhich form the main bulk of the Rocca Busambra car-bonate ridge. They include:

a) Marabito limestones (ITO on the map). Dolomitizedupper Triassic sponge-bearing reef limestones (figs. 8a, b

and tab. 3), 30 metres thick, outcropping in the eastern-most sector of the Rocca Busambra (Pizzo Marabito);

b) Inici Formation (INI on the map). White peritidallimestones, up to 400 m thick, display different shallow-water lithofacies (figs. 8c, d) organized in shallowingupward sequences. The fossil content (tab. 3) dates thesebeds to the Hettangian-Sinemurian time interval. Thetop of the white peritidal limestones appears to be dis-sected by a dense network of neptunian dykes. Impres-sive examples of these neptunian dykes are seen in theRocca Argenteria quarry, where WENDT (1971) hasrestored the chronological evolution of the filling sedi-ments. A regional unconformity marks the top of theInici Formation which is capped by a blackish Fe-Mncrust. The latter is interpreted as an hardground relatedto the carbonate platform drowning (JENKYNS, 1970a)and due to probable anoxic events and bioerosion (DISTEFANO & MINDSZENTY, 2000);

c) the Inici Fm limestones are unconformably fol-lowed by the Jurassic condensed deposits of the BuccheriFm. This unit includes two members:

i) Bositra limestones (BCH1 on the map). A fewmetres thick, reddish-brown to grey wackestone/pack-stone (figs. 8e, f) and local laminitic stromatolites withrich pelagic fauna (tab. 3) of Bajocian-Early Kimmerid-


TABLE 2

Lithostratigraphic characters of the Cretaecous-Miocene formations of the Sicanian succession.

Main lithology Environ. Fossil content Age

50-1

50m

outer shelf plankton forams (MMi 5-7 biozones), calcareous nannofossils (MNN 6a, MNN 7a and Minilytha convallis biozones)

Lower Tortonian-Upper Langhian

40-8

0m

coas

tal t

o de

ltaic

influ

ence

d by

tid

al cu

rren

ts

Large benthonic forams (Operculina complanata, Miogypsina spp., Nephrolepidina spp.), plankton forams (Globoquadrina dehiscens dehiscens-Catapsydrax dissimilis, Globigerinoides trilobus, Praeorbulina glomerosa s.l. biozones)

Langhian-Upper Aquitanian

100-

150m

slope

to

oute

r she

lf plankton forams (Globoquadrina dehiscens dehiscens-Catapsidrax dissimilis, Globorotalia kugleri biozones), calcareous nannofossils (NP 24-25 biozones); nummulitids and Nephrolepidina spp.

Lower Aquitanian-Chattian

AM

Md Breccias and bioclastic

coarse-grained packstone large benthonic foraminifers (nummulitids), algae (Subterraniphyllum thomasi ) Lower Oligocene

AM

Mc grey wackestone and marls

with Cancellophycusplankton forams (Cassigerinella chipolensis-Pseudohastigerina micra biozones) Lower Oligocene

AM

Mb white wackestone with black

chert nodulesplankton forams (Turborotalia cerroazulensis s.l., Globigerinatheka semiinvoluta, Truncorotaloides rorhi biozones)

Upper-Middle Eocene

AM

Mm

calcareous megabreccias Lower Maastrichtian-Campanian

AM

Ma reddish mudstone and marls

in thin strata Lower Eocene-Upper Cretaceous

Grey-blackish thin bedded cherty limestones, green-whitish marls, packstone with Aptychus fragments up

to 5

0m deep-water basin

plankton forams (Globigerinelloides algeriana, Ticinella primula, Biticinella breggiensis biozones), radiolarians, sponge spiculae, belemnites (Duvalia lata ) and mollusc shells

Albian-Aptian

Glauconitic grainstone-packstonea, calcareous and quartzitic sandstones and greenish siltitic marls

Grey and sky-blue clays, clayey marls and sandy marls

Hybla Fm. (HYB)

plankton forams (Globotruncana elevata, Glt. aegyptiaca, Morozovella subbotinae, M. formosa formosa biozones)

Fms

deep

-wat

er b

asin

inte

rest

ed b

y gr

avita

tiona

l pr

oces

ses (

debr

is an

d gr

ain fl

ow)

Am

erill

o Fo

rmat

ion

up to

200

m

Cardellia marls (RDE)

Corleone calcarenites

(CCR)

San Cipirello marls (CIP)

Lim

esto

nes,

calca

reou

s mar

ls

Marls and dark green marly clays with ironized nodules; intercalations of turbiditic packstone 20-100 cm-thick

48 L. BASILONE

Fig. 4 - Microfacies of the Cretaceous-Miocene deposits of the Sicanian succession: a) mudstone with radiolarians, planktonic foraminifersand sponge spiculae (Hybla Formation, Contrada Giardinello, scale bar 1mm); b) wackestone with globotruncanids and heteroelicids (scagliarossa lithofacies, Amerillo Formation, Piano della Tramontana, scale bar 1mm); c) packstone with benthic macroforaminifers, calcareous algae, corals and intraclasts (nummulitid breccias lithofacies of the Amerillo Formation, Monte Barracù, scale bar 1mm); d) packstone withbenthic macroforaminifers, coral fragments and intraclasts (calcareous turbidite intercalations in the Cardellia marls, Contrada Pirrello,southern limb of Rocca Busambra, scale bar 1mm); e) and f) grainstone with benthic foraminifers, algae fragments, intraclasts and glauconitic grains (Corleone calcarenites, Rocca dei Maschi, scale bar 1mm).


Fig. 5 - Comparison between the Sicanian Amerillo Fm outcropping at Monte Barracù and Piano della Tramontana (eastern Rocca Busam-bra ridge, see location map). Impressive characters of the main lithofacies are shown: a) strongly deformed reddish limestones and marls(red scaglia lithofacies, Portella del Vento, Rocca Busambra); b) thin white cherty limestones (white scaglia lithofacies, Monte Barracù); c) rhythmic alternations of thin grey limestones with ichnofacies (Cancellophycus isp.) and greenish marly clays (Monte Barracù); d) cal-carenites and breccias with nummulitids (Monte Barracù); the m-thick resedimented bodies show erosional lower boundary, parallel andoblique lamination and gradational structures.

gian age (WENDT, 1969). They outcrop mostly in thePiano Pilato region. This lithofacies is easily recognizedby the dark dm-sized nodules that are encrusted by ferro-manganese oxides (WENDT, 1963; JENKYNS, 1970b, 1971)and the interlayered cm-sized dark Fe-Mn crusts;

ii) Saccocoma limestones (BCH3 on the map) are thick-bedded, tabular and massive red-to-grey pelagic crinoid-

bearing grainstone-packstone, a few metres thick, outcrop-ping along the whole ridge. The rich fossil content (tab. 3)dates these beds to Late Kimmeridgian-Tithonian age;

d) crinoidal limestones (RND on the map) includered-to-grey massive grainstone-packstone, 50-80 cm thick,in places encrusted by Fe-Mn layers; they are, locally, thebasal sediments of the Buccheri Fm.

Uppermost Jurassic-Eocene pelagic carbonate de positsof the Lattimusa, Hybla and Amerillo Fms. (tab. 3, respec-tively LTM, HYB and AMM on the map), follow upwards.

A prominent thick massive, tabular and/or lenticular-shaped Upper Cretaceous carbonate megabreccia is inter-layered into the Amerillo Fm.

The Amerillo Fm, in its turn, is unconformably co -vered by the Lower-to-Middle Miocene «Corleone cal-carenites» and topwards the San Cipirrello marls.

Three main sections (fig. 9a), having different tectono-sedimentary patterns, are described to illustrate the vari-able stratigraphic settings of the Rocca Busambra ridge.

a) Piano Pilato section

It is located at the westernmost side of Rocca Busam-bra (fig. 9b). The succession shows a Jurassic «condensedpelagic» facies association (Buccheri Fm), unconformablyfollowed by both the Upper Cretaceous pelagic limestones(Amerillo Fm) and by the Lower Miocene reworkedpelagic deposits («Corleone calcarenites»). This sequencerests unconformably above the sub-horizontal beds of theInici Fm peritidal limestones.

Synsedimentary tectonics originated several, south-dipping, largely subvertical (60-80° steep) WNW-ESE- oriented paleofaults displacing the Inici Fm deposits (fig. 6 on the frame of the map). The fault planes are sealedby Upper Jurassic, reworked, pelagic deposits (upper mem-ber of the Buccheri Fm) that lie with a buttress uncon -formity against the hanging-wall scarp of the fault plane.The western side of Piano Pilato (Pizzo Nicolosi) showsseveral WNW-ESE faults that downthrow the Jurassic car-bonates, giving rise to a horst and graben setting (PizzoNicolosi and Rocca Ramusa graben structures, fig. 3 onthe frame of the map); the morphotectonic depressions arefilled by a 40 m-thick package of Upper Cretaceous pelagicdeposits of the Amerillo Fm. The latter directly onlaps theJurassic floor of the depressions; in the meantime theycrop out, with buttress unconformity, against the subverti-cal walls (fig. 4 on the frame of the map).

b) Rocca Busambra-peak section

Located in the central sector of the ridge (fig. 9b), theRocca Busambra-peak shows the carbonate megabrecciasthat either rest unconformably over the Jurassic condenseddeposits of the Buccheri Fm or abruptly onlap the peritidallimestones of the Lower Jurassic Inici Fm (fig. 5 on theframe of the map). At places, the former fill up shallow,channelled gullies. The mapped synsedimentary tectonicstructures are subvertical ENE-WSW normal faults (with afew to several metres of downthrow) that dissect the IniciFm peritidal limestones and the Jurassic condensed Buc-cheri Fm deposits (fig. 5 on the frame of the map).

c) Pizzo Marabito section

Located along the easternmost side of the ridge (fig. 9b), the rock succession deeply differs from those

50 L. BASILONE

Fig. 6 - Detailed stratigraphic sections of the Cardellia marls, measuredand sampled along the Monte Cardellia proposed type section (see location map) and Case Bifarera outcrop (north of Rocca Busambra).

previously described. The Upper Triassic reef of theMarabito limestones is unconformably overlain, with but-tress unconformity, by both the Buccheri and LattimusaFms (fig. 8 on the frame of the map). Synsedimentary tec-tonic features in the Upper Triassic reef limestones arefissures, neptunian dykes and in situ breccias. ENE-WSWtrending pre-Upper Jurassic subvertical fault planes arealso present (fig. 8 on the frame of the map).

MIOCENE FOREDEEP (WEDGE-TOP BASIN) DEPOSITS

Upper Miocene deltaic conglomerate, sandstone andclay, pertaining to the Castellana Sicula and TerravecchiaFms. (tab. 4), are mapped in the southwestern area.

The Castellana Sicula Fm (SIC on the map), is aclayey sequence with quartz sandstone intercalations, afew metres to 150 m-thick. It unconformably overlies theSan Cipirello marls at Vallone del Poggio (west of thetown of Corleone), Trentasalme and Bicchinello areas(immediately to the south and south-west of PizzoNicolosi), or the numidian flysch at Contrada Pirrello andCasale (south of Rocca Busambra) and the Sicilidideposits at Contrada Bifarera (northern edge of the map).The poorly and badly-preserved fossil content dates thesedeposits as Late Serravallian-Early Tortonian.

The Terravecchia Fm (TRV1 and TRV2 members), ismapped at Cozzo Riddocco and Vallone del Poggio(southwest of Corleone). The basal member consists ofcalcareous and siliceous graded conglomerates; these dis-play lenticular and pinch-out geometries and thicknessvariability from a few metres to up to 20 m. The conglom-erate elements, mostly consisting of glauconitic «Cor-leone calcarenites», suggest that the source areas of the clastic material are those of the substrate that theyoverlie. Differently, the same deposits outcropping atContrada Bifarera (north of Rocca Busambra, imme -diately off the map) consist of siliceous and quartz-arenitic elements, suggesting an overall cannibalization ofthe quartz-sandstones of the numidian flysch.

The overlying member displays cross-laminated sand-stones, up to 30 m-thick, laterally and upwards passing tosiltitic and grey clays, pertaining to the pelitic member (out-cropping just outside the edge of the map). The fossil con-tent of the clayey lithologies indicates their Late Tortonian-Early Messinian age (DI STEFANO & CATALANO, 1978). Thebasal boundary of the Terravecchia Fm is an erosionalunconformity above the older rock units; it is well shown atthe Vallone del Poggio area, where the formation overliessandstones and clays of the Castellana Sicula Fm.

QUATERNARY DEPOSITS

Quaternary-to-Recent deposits, developed in theframe of the morphogenetic evolution of the area, aremapped in detail with the aim of supplying basic infor-


Fig. 7 - Proposed type section of the Corleone calcarenites at Rocca deiMaschi (town of Corleone). The columnar section displays the sedimen-tological and lithological characters of the several lithological intervalsand facies associations distinguished, and the cyclic arrangement of thesuccession (T-R sequence cycles and parasequences). In the picture be-low (Rocca dei Maschi natural section) are overprinted the lithologicalintervals (a to d), the T-R cycles (R1, R2) and the parasequence cycles(white arrows); The time interval of the uppermost cycle is based on theoccurrence of the markers of the Praeorbulina glomerosa s.l. biozone.

52 L. BASILONE

TABLE 3Lithostratigraphic characters of the Triassic-Miocene formations of the Trapanese Rocca Busambra succession.

Main lithology Lower boundary Fossil content Age

brown and dark clayey marls, locally with glauconite

conformable with CCR

15-1

50m planktonic forams (MMi 5-MMi 9 and MMi 11

biozones) calcareous nannofossils (MNN5b-MNN 7b and Minylitha convallis biozones)

Upper Langhian-Lower Tortonian

yellow-green glauconitic globigerinid-bearing packstone-grainstone

buttress unconformity with INI 30

m planktonic forams (Globigerinoides trilobus, Praeorbulina glomerosa s.l. biozones)

Burdigalian-Langhian

white and red planktonic foraminifers-bearing wackestone and calcareous megabreccias

paraconformable on HYB, buttress unconformity with BCH and INI

5-50

m

plankton forams (Rotalipora reicheli, Rotalipora cushmani, Globotruncana ventricosa, Turborotalia cerroazulensi s.l. biozones), calcareous nannofossils (CC10 biozone)

Cenomanian- Maastrichtian and Upper Eocene

marls and cherty limestones; bio-intraclastic (Aptychus and mollusc fragments) floatstone

transitional on LTM

>50

m planktonic forams (Globigerinelloides algeriana, Biticinella breggiensis ), calcareous nannofossils (CC7-8 biozones)

Aptian-Albian

pink to white thin bedded cherty mudstone, locally intraformational pebbly mudstone and resedimented bioclastic breccias

Transitional on BCH3; onlap and buttress unconformity with INI and ITO

3-15

mcalcareous nannoplankton (Nannoconus steinmanni ), radiolarians, belemnites, ammonites and calpionellids (Calpionella, Calpionellopsis and Calpionellites biozones)

Upper Tithonian-Neocomian

BCH

3 tabular and massive red to grey pelagic crinoids-bearing grainstone/packstone

downlap or buttress unconformity with the BCH1, INI, ITO 2-

10m Saccocoma sp., benthic forams (Protopeneroplis

striata), Globochaete sp., Aptychus sp., brachiopods, belemnites and ammonites

Upper Kimmeridgian- Lower Tithonian

BCH

1

reddish, brown to grey bioclastic wackestone/packstone with dark dm-sized Fe-Mn nodules, laminitic stromatolites

onlap with RND and with the blackish Fe-Mn crust capping the Inici Fm.

0.5-3

m

ammonites (S. humpresianum, G. garantiana, P. parkinsoni, R. anceps biozones), radiolarians, thin-shelled pelagic bivalves (Bositra buchi) , protoglobigerinids

Bajocian-Lower Kimmeridgian

Red to white massive grainstone packstone, encrusted by Fe-Mn oxides

onlap with INI

0-0.8

m

Crinoid ossicles and plates (Pentacrinus sp.), benthic foraminifera and ammonites Toarcian

:algae and mollusc-bearing wackestone-packstone, stromatolithic and loferitic packstone, oolitic and bioclastic packstone/grainstone

not outcropping. In adjacent areas is paraconformable on Sciacca Fm.

400m

gastropods, brachiopods, ammonites (Arietites bucklandi, Echioceras raricostatum ), calcareous algae (Cayeuxia sp., Thaumatoporella parvovesiculifera, Paleodasycladus mediterranu ), benthic foraminifera (Involutina liassica )

Hettangian-Sinemurian

dolomitized sponge-bearing boundstone. It becomes a clast-supported in situ breccias

not outcropping. A lateral transition with Sciacca Fm. is inferred 30

m

Calcareous sponges (Follicatena irregularis, Panormida sp., Cheilosporites tirolensis ) associated with rare corals and calcareous algae

Norian-Rhaethian

Crinoidal limestones (RND)

Inici Fm. (INI)

Marabito limestones (ITO)

Fms

Bucc

heri

Fm.

San Cipirello marls (CIP)

Corleone calcarenites (CCR)

Amerillo Fm. (AMM)

Hybla Fm. (HYB)

Lattimusa (LTM)

TABLE 4Lithostratigraphic characters of the Miocene syntectonic deposits.

Main lithology Environ Fossil content Age

TRV 2

Yellowish badly cemented quartz sandstones in thick beds, with planar and crossed lamination and bioturbation and thin conglomerate intercalations up

to 3

0m

TRV 1

Large-size (decimetric) grey and withish calcareous and siliceous conglomerates, frequently embriciated and graded; the elements deriving, mostly, from dismantling of the CCR up

to 2

0m

Grey, white-yellowish clays and sandy clays with poorly and bad-preserved benthic foraminifera (Ammonia inflata, Elphidium spp.) with, locally, thick intercalations of quartzitic-micaceous sandstones up

to 1

50m Open

platform-to-slope

Planktonic forams (Neogloboquadrina praeatlantica, Neogloboquadrina acostaensis biozones)

U.Se

rrava

llian-

L.To

rtoni

anU

pper

Tor

toni

an-L

ower

M

essin

ian

Castellana Sicula Fm. (SIC)

Fms

Terra

vecc

hia F

m.

Fluv

io-d

eltaic

, pas

sing

upwa

rds t

o op

en m

arin

e

Planktonic forams (MMI5- MMI 11 biozones); calcareous nannofossils (MNN 6a, MNN 7a and Minilytha convallis (pars), Reticulofenestra rotaria biozones). The fossil conten has been found in the upper pelitic member, not outcropping in the map


Fig. 8 - Characteristic lithofacies and microfacies of the Upper Triassic-Lower Jurassic carbonate shallow-water deposits (Marabito lime-stones and Inici Fm) and the Jurassic «Rosso Ammonitico» deposits (Buccheri Fm) outcropping along the Rocca Busambra ridge: a) dolomi-tized Upper Triassic sponge-bearing boundstone (A) followed upwards by oolitic grainstone (B), Pizzo Marabito. The boundary between thetwo lithofacies is an erosional surface; b) the same facies as above, showing cement (X) filling the space in between sponge elements; c) stro-matolite lithofacies of the Lower Jurassic peritidal limestones (Inici Fm), intersected by subvertical neptunian dyke (hammer); d) oolitic andbioclastic grainstone with benthic foraminifers of the Inici Fm; e) wackestone with ammonites, radiolarians, Aptychus and thin-shelled frag-ments of the Bositra limestones (lower mb of the Buccheri Fm); f) packstone with thick-shelled molluscs, echinoid fragments, benthicforaminifers (Saccocoma limestones, upper mb of the Buccheri Fm).

mation for territorial planning purposes. The rocks aregrouped in synthems (UBSU, sensu SALVADOR, 1994), asrecently described by DI MAGGIO et alii (2009).

Continental and alluvial deposits, originated fromthe last postglacial phase, are grouped in the Capo Plaiasynthem.

The synthem encompasses: a) scree and debris flowoutcropping along the foot of the carbonate massifs(AFLa on the map); b) eluvial products and colluvialdeposits, consisting of heterometric clasts, welded in aclayey matrix (AFLb on the map); these deposits are dueto in situ alterations of the substrate and to geomorpho-logical side processes; c) alluvial deposits, consisting ofclays, sands and pebbly grains, outcropping along therivers or forming terrace deposits (AFLc on the map); d) active and quiescent landslides (AFLd on the map),related to rotational and deep-seated gravitational pro -cesses, are widely diffused in the study region.

TECTONICS

A structural map (fig. 9 on the frame of the map) andsome geological cross-sections (figs. 10, 14 and geologicalcross-section AA” on the frame of the map) display the tec-tonic setting of the study area and the geometrical relation-ships among the mapped rock units. The structural relation-ships among the tectonic units are recognized also with thehelp of the published subsurface seismic data. The tectonicedifice includes (from the top): Middle-Upper Miocene syn-tectonic deposits; Sicilide nappe, that overthrusts thenumidian flysch tectonic unit at Cozzo Arcuri (northernedge of the map). The numi dian flysch tectonic wedge over-thrusts the Sicanian Corleone-Barracù tectonic unit. Theseunits, in turn, tectonically rest above the Trapanese-derivedcarbonate platform Busambra tectonic unit.

When carefully investigated, each one of the main tectonic units displays different structural elements andinternal deformations.

1) The syntectonic deposits (Castellana Sicula andTerravecchia Fms), mostly outcropping in the south- western corner of the map, are deformed by successivefolds and, mainly, by NE-SW to NW-SE oriented strikeslip and normal faults. The geological sections across thearea (fig 10a and geological cross-section AA” on theframe of the map) show how the deposits, mapped northof the Rocca Busambra ridge, unconformably seal theSicilide and numidian flysch rock bodies; while, thedeposits mapped at Vallone del Poggio-Cozzo Riddocco(south of Rocca Busambra) unconformably lie above theMiddle Miocene Sicanian deposits.

2) The large, thick numidian flysch tectonic unit(from now on named the NFU unit), overthrusts, along anearly flat surface, the Miocene San Cipirello marls and«Corleone calcarenites» of the Sicanian Corleone- Barracùtectonic unit, as shown in the Pirrello and Lavancheregions (to the south of Rocca Busambra), at Cozzo Zuc-carone, at Tagliavia, Bifarera (original tectonic window)and at Scalilli (north-western corner of the map). AtCasale (immediately south of Piano Pilato), Puntale l’Apeand at Cozzo Tondo (northern side of the Rocca Busam-bra-peak) the unit, tectonically, rests above the Upper Triassic Mufara Fm folded beds (geological cross-sectionAA” on the frame of the map and fig. 10d). In the Boscodella Ficuzza region, the NFU unit displays large (deca-metric wavelength) NW-SE- oriented folds, back-vergingNEwards (fig. 10b). NE-SW-oriented strike-slip faults,related to a southwest-verging fold-system, dissect thequartz-sandstone numidian flysch intercalations at CozzoDonna Giacoma and at Bo sco della Ficuzza.

3) The Corleone-Barracù tectonic unit (from now onnamed the CBU unit) is mapped: a) at Contrada Bifarera(northwestern corner of the map), along the Cozzo Zuc-carone structure and around the town of Corleone, whereit is represented by Oligo-Miocene carbonate-clastic rocks;b) at Piano della Tramontana-Pizzo di Casa and MonteBarracù, where the unit is made of thick, and stronglydeformed, Cretaceous-to-Lower Oligocene pelagic lime-stones and c) along the steep scarps of the Rocca Busam-bra ridge, where only scattered patches of the Mufara Fm,tectonically overlying the Miocene San Cipirrello marls,are present.

At Contrada Bifarera the Sicanian rocks are thrust,along high-angle reverse faults, over the already emplacednumidian flysch tectonic unit (fig. 10a).

The main setting of the CBU unit, characterized byasymmetric folds, internal low-angle reverse faults anddécollement surfaces, is outlined by two culminations:

i) the Cozzo Zuccarone is an E-W and WNW-ESE oriented antiform with narrow and asymmetric south-verging folds (geological cross-section AA” on the frameof the map and fig. 10a); the structure is evidenced by the occurrence of the carbonate «Corleone calcarenites»layer, sandwiched by two marly clay levels (Cardelliamarls and San Cipirrello marls). The antiform is also dis-sected by NW-SE right-handed strike-slip faults, obliqueto the major fold hinges. Locally (Cozzo Spolentino), lowangle thrust planes imbricate the Oligocene-Miocene clastic-carbonate sequence, showing splay geometries(fig. 10c). This tectonics confirm that the Oligo-Mioceneclastic sequence appears wholly detached from the under-lying Amerillo Fm substrate (figs. 10a-c).

ii) Piano della Tramontana is a W-E and WNW-ESEoriented antiform with hectometric wavelength (fig. 11).

54 L. BASILONE

Fig. 9 - a) Stratigraphic sections measured and sampled along the Roc-ca Busambra ridge. In b) detail of the different regions distinguished.


Fig. 10 - Tectonic relationships among the outcropping structural units in the study region. The Trapanese Busambra carbonate platform tectonic unit (BU) is the lowermost structural level of the tectonic edifice. This unit, in its turn, is overthrust, along low-angle tectonic surfaces, by the Sicanian Corleone-Barracù (CBU) and numidian flysch (NFU) tectonic units. The present-day structural setting is due to thedeep-seated high-angle reverse faults with lateral component of movement. Traces of the a, b, c, d and of fig. 14 geological cross-sections arelocated in the structural map (e).

Fig. 11 - Piano della Tramontana antiform, eastern side of Rocca Busambra. It is possible to see the tectonic contact between the Pizzo diCasa Sicanian deposits (AMMm: calcareous megabreccias, AMMa red scaglia and AMMb white Scaglia of the Amerillo Fm) with the numi -dian flysch (Geraci Siculo mb, FYN5). At Piano della Tramontana the ENE-WSW oriented anticline is displaced by NS faults.

The core of the major anticline displays a south-vergingnarrow fold-system of chevron and box-fold type, furtherdisplaced by south-verging low-angle reverse faults (fig. 12).Disharmonic surfaces separate the more ductile upperMesozoic-Paleogene strata from the lower Mesozoic deep-water limestones (mainly Scillato Fm). The antiform isbounded northwards by a transpressional high-angleback-thrust that downthrows the numidian flysch wedgewith respect to the pelagic limestones (fig. 11). West-wards (near the Rocca Busambra-peak), the previously-

mentioned Piano della Tramontana antiform overthruststhe Busambra tectonic unit, as evidenced by the pericli-nalic culmination of the folded Sicanian thin-beddedlimestones (fig. 10d).

4) The Busambra tectonic unit (from now on namedthe BU unit) develops along the Pizzo Nicolosi-PizzoMarabito ridge as an E-W to NW-SE trending large car-bonate antiform. The structure is bounded northwardand southward by E-W and WNW-ESE high-anglereverse faults, which separate the carbonate platformunit from the adjacent numidian flysch and Sicanianunits (figs. 10a, b, d and fig. 6 on the frame of the map).Eastwards the unit disappears beneath the Sicanian Cre-taceous-Lower Oligocene pelagic limestones outcroppingat Piano della Tramontana. At Pizzo Marabito the car-bonate structure plunges to the east disappearingbeneath the numidian flysch unit.

The main tectonic lineaments mapped along theBusambra unit are:

– WNW-ESE and NW-SE syndepositional exten-sional-to-transtensional faults and fractures (CATALANO& D’ARGENIO, 1982b; BASILONE et alii, 2010) dissectingthe Mesozoic carbonates at different stratigraphic levels(figs. 4-8 on the frame of the map);

– large N-S and NNW-SSE oriented structures fold-ing the Mesozoic limestones.

– E-W to NW-SE transpressional, high-angle fault,characterized by several hundreds of metres of down-throw, associated to vertical fault line scarps (Busambrafault, fig. 13). The south-dipping fault planes display kine-matic indicators, suggesting dextral movements along thefault planes (CATALANO et alii, 2010a, b).

– WNW-ESE, W-E and WSW-ENE striking andsouthward-verging, high-angle thrust faults characterizethe southern side of Rocca Busambra (fig. 10a and fig. 6on the frame of the map);

– NS and NNE-SSW oblique faults with left-lateralcomponent of motion (tear faults?), dipping to the E and

56 L. BASILONE

Fig. 12 - South-verging chevron folds and reverse faults in the pelagic Amerillo Fm at Pizzo di Casa (eastern side of Rocca Busambra ridge).

Fig. 13 - Morphostructural scarp of the Busambra high-angle reversefault, along which the carbonate unit overthrusts the numidian flysch tectonic unit. Northern side of Rocca Busambra.

ESE, dissect the central and eastern sectors of the ridge.These faults are antithetic to the main dextral transpres-sional E-W system.

– SW dipping, NW-SE trending normal faults displace the ridge structure, mostly in its westernmostsector.

DISCUSSIONS

The recognized surface structural setting is consistentwith the buried structure reconstructed in the studyregion (fig. 14) according to geological interpretations ofthe seismic profiles crossing the area.

Comparing these interpretations provides a betterunderstanding of: 1) the structural setting and the back-thrust structures of the Rocca Busambra, 2) its paleotec-tonic evolution, 3) the deformation style of the Sicanianunits and 4) the relationships between the Upper Miocenewedge-top basins deposits and the deformed substrate.

1) The Busambra unit, as described in this paper, isthe culmination of a larger anticline, bordered by two,main transpressive faults of a south-verging ramp struc-ture (figs. 10a and 14 and geological cross-section AA” onthe frame of the map). The E-W high-angle back-vergingreverse fault (Busambra fault, figs. 10a and 13), whichgradually flattens with depth (see seismic interpretationsby AGATE et alii, 1998a; CATALANO et alii, 2000 andAlbanese et alii, 2005), might be considered as a deep-seated structures.

The resulting structural setting is different comparedto the previous interpretations: MASCLE (1979) described

the BU unit as a sedimentary klippen resedimented in theMiocene marls basin. CATALANO et alii (1978), ROURE etalii (1990), LENTINI et alii (1994), MONACO et alii (2000)interpreted the carbonate platform Busambra tectonic unitas primarily overthrusting the Sicanian rock units. How-ever, AGATE et alii (1998a) and CATALANO et alii (2000),described the Sicanian units as overthrusting the Tra-panese Busambra unit, based on seismic profiles interpre-tation. The local setting of the Trapanese rock units abovethe Sicanian ones is a late effect of the structural «envelop-ment» (out of sequence) between the two rock units.

The previously-mentioned transpressional Busambrafault was described as a normal fault (ROURE et alii,1990), or a deep strike-slip fault (MONACO et alii, 2000), ora deep-seated positive flower structure in the frame of themain strike-slip tectonics (NIGRO & RENDA, 2001).

2) In the Rocca Busambra ridge the Mesozoic syn -sedimentary tectonics and the restored depositional set-ting suggest the occurrence of a stepped fault marginwith condensed sequences (Piano Pilato), passing to ahorst and graben system (Pizzo Nicolosi) and to slopeareas (Pizzo Marabito). The latter are characterized by ascalloped upper slope passing to a base-of-slope environ-ment (Rocca Busambra-peak).

To consider the Piano Pilato stepped margin as the slopemargin of the Barracù Sicanian basin (as proposed by MAR-TIRE & BERTOK, 2002 and BERTOK & MARTIRE, 2009)appears difficult due to the structural setting di scussed above(the Sicanian units regionally overthrust the Trapanese car-bonate platform rock units, see also BASILONE, 2009).

The Mesozoic faults are reactivated by the deep-seated transpressional structures, as proved by meso -


Fig. 14 - a) The seismic profile across the Rocca Busambra-Monte Cardellia area (see trace in fig. 10a) shows the structural relationshipsbetween the Trapanese carbonate platform Busambra unit (BU) and the deep-water Sicanian Corleone-Barracù unit (CBU); b) The geologicalsection, crossing the same area, shows the surface interpretation of the topmost part of the seismic profile.

structural analyses carried out along the Rocca Busambraridge (BASILONE et alii, 2010). The latter show how thefaults involving the Mesozoic deposits display the sametrend of the Late Tertiary reverse faults crossing themapped area. Similar features are described in adjacentregions (e.g. Kumeta ridge, AVELLONE et alii, 2010).

3) The S- and SW-wards vergent Sicanian Corleone-Barracù tectonic unit is, on the whole, thrust over the carbonate Busambra tectonic unit along a partly buriedlow-angle surface (figs. 10a and 14a). Based on the fieldobservation and on the seismic profile interpretation (fig. 14), a duplex geometry of the tectonic unit is pointedout. The duplex tectonic style of the CBU is in agreementwith similar features described in the eastern SicanianMountains (VITALE & GIAMBRONE, 1995; VITALE, 1996;CATALANO et alii, 1996).

The detachment surfaces, within the deep-water Sica -nian succession, disconnect the more ductile upper Meso-zoic-Paleogene strata from the lower Mesozoic deep-waterlimestones. As a consequence, uncoupled levels of the CBUunit overlie the main thrust surface above the BU unit (as itis possible to observe in the geological map, along thesouthern limb of the Rocca Busambra ridge and in fig. 10d).

The originally flat thrust surface and the local décolle-ments are, at present-day, tilted and deformed according tothe late deformation of the carbonate platform substrate.

In detail, both the Oligo-Miocene roof thrust and theCretaceous-Eocene horses were later redeformed givingrise to the main E-W and WNW-ESE plicative structuressuch as the splay structures (Cozzo Spolentino, fig. 10c),and the associated fold systems (e.g. Cozzo Zuccaroneantiform, fig. 14 and Piano della Tramontana antiform).

4) The Middle-Upper Miocene deposits (Castellana Sicu -la and Terravecchia Fms) are believed to be depo sited in awedge-top depozone (CATALANO & D’ARGENIO, 1990; BU -TLER & GRASSO, 1993). The mapped outcrops overlie differ-ent substrata and are characterized by lithological differences(nature of the conglomerates). These features demonstratethat these deposits were formed in separated basins, origi-nally faraway from each other and respect to the present-daylocation, with different source areas of the clastic materials.

Timing of deformation

The tectonic edifice in the study area is the result ofseveral deformational events, from the Triassic to thePleistocene. These have deformed the sedimentary suc-cessions that settled along the African continental marginpaleogeographic zone. The timing of the deformation isconstrained by the age of the foredeep basins and the firstunconformable deposits.

Preorogenic phase

During the Mesozoic-Early Miocene continental mar-gin phase, synsedimentary tectonics accompany deposi-tions in carbonate platform-basin systems. It is clearlyput in evidence by both the syntectonic deposition alongthe Trapanese carbonate platform Rocca Busambra suc-cession and the sudden thickness variations of the out-cropping Sicanian succession.

Postcollisional phase

This phase started with the continental margin defor-mation, following the latest Oligocene-Early Miocene

counter-clockwise rotation of Corsica-Sardinia and its col-lision with the African margin. During the collision timetwo main tectonic events occur. The older documenteddeformation relates to the emplacement of the Sicilidiunits above the Lower Miocene numidian flysch. The lat-ter is, at present time, stacked above Lower Tortonianmarls, representing the top of the Sicanian Units. There isa large consensus about the decoupling of the numidianflysch from its Imerese (or more internal) Meso-Cenozoiccarbonate substrate. Both the Imerese units and thealready detached numidian flysch units were emplacedabove the Sicanian units after the Early Tortonian (figs. 1and 2 on the frame of the map and MASCLE, 1979; CATA-LANO & D’ARGENIO, 1978; ROURE et alii, 1990). The deep-sea rock bodies of the Sicanian domain appear thrust overthe Lower Tortonian marls pertaining to the carbonateplatform Trapanese Busambra succession. The latterappear involved in the deformation after the Sicanianunits emplacement, as put in evidence by the alreadydescribed local thrusting of the carbonate platformBusambra rock unit over the Sicanian Barracù tectonicunit. The Sicanian rock units appear redeformed, after theMiocene early tectonic event, as put in evidence by differ-ent orientation trends of the fold systems. This secondplicative event caused the deformation of the Messinian-Lower Pliocene deposits, as shown in the surroundings ofthe study region, and took place in the Late Pliocene.More recent extensional tectonics (Early Quaternary timesin western Sicily) are not clearly discernible in the area.

CONCLUSIONS

The geological map (1:37.500 scale) of the RoccaBusambra-Corleone region (central-western Sicily) is pre-sented here, based on facies analysis, physical stratigra-phy, biostratigraphy and structural analysis. The map,originally compiled at a 1:10,000 scale, represents a newapproach to the geology of the region.

A detailed mapping and the stratigraphy illustrate theseveral outcropping lithostratigraphic units (more than22 formations and members), some proposed type sec-tions and the characters of the Piano della Tramontana(eastern side of the Rocca Busambra ridge) deposits aspertaining to the Sicanian succession.

The mesoscopic and large-scale structural analysisdepicts a tectonic setting comparable with subsurfacegeometries (suggested by seismic data). The collecteddata restore a tectono-sedimentary evolution from Meso-zoic extensional rifting-phase to Late Tertiary compres-sive belt deformation:

– extensional-to-transtensional Mesozoic-Lower Mio -cene tectonic pulses have punctuated the tectono-sedi-mentary evolution of the Rocca Busambra area;

– thin-skinned tectonics (shallow-seated structures)have developed with duplex and embricate fan geometryof the Sicanian deep-water carbonate and numidian flyschtectonic units. These units have progressively overthrustthe Trapanese carbonate platform Busambra unit duringthe Late Miocene;

– deep-seated structures originated from a transpres-sional Pliocene tectonic event have deformed the Busam-bra unit at a depth. The late tectonics involve the alreadyemplaced units (Sicilidi, numidian flysch and Sicanianunits), that, in turn, are passively bent and redeformed.

58 L. BASILONE

ACKNOWLEDGMENTS

This research was supported by PRIN 2006, CARG project andMiur (ex 60%) 2006 grants (coord. Prof. R. Catalano). Two referees,Profs. C. Monaco and L. Ferranti, are acknowledged for their usefulcomments and suggestions, that improved the manuscript. Thanksare due to Profs. R. Sprovieri and E. Di Stefano for their biostrati-graphic support and C. Di Maggio for his geomorphological comments.S. Pierini helped in the graphics of the map.

REFERENCES

AGATE M., BASILONE L., CATALANO R., FRANCHINO A., MERLINI S. &SULLI A. (1998a) - Ipotesi sulla condizione strutturale della RoccaBusambra. In: R. CATALANO & G. LO CICERO (Eds.). La Sicilia,un laboratorio naturale nel Mediterraneo. Strutture, Mari,Risorse e Rischi. Guida alle Escursioni del 79° Congr. Nazionaledella Soc. Geol. It. - La Sicilia Occidentale, 1, 71-78. Mondello(Palermo, Italia), 21-23 Settembre 1998.

AGATE M., BASILONE L., CATALANO R., FRANCHINO A., MERLINI S. &SULLI A. (1998b) - Deformazione interna delle Unità Sicanenell’area tra Corleone e Monte Colomba. In: R. CATALANO & G. LOCICERO (Eds.). La Sicilia, un laboratorio naturale nel Mediterra-neo. Strutture, Mari, Risorse e Rischi. Guida alle Escursioni del79° Congr. Nazionale della Soc. Geol. It. - La Sicilia Occidentale,1, 79-86, Mondello (Palermo, Italia), 21-23 Settembre 1998.

AGNESI V., MACALUSO T., MONTELEONE S. & PIPITONE G. (1978) -Espansioni laterali (lateral spreads) nella Sicilia Occidentale.Geol. Applicata e Idrogeologia, 13, 319-326.

ALBANESE C., AVELLONE G., BASILONE L., CATALANO R. & SULLI A.(2005) - Triangle zone and passive-roof duplexes in central- western Sicily? new insight from seismic interpretation. Abs. vol.,p. 51. Convegno FIST-Geoitalia 2005.

ALLEMAN F., CATALANO R., FARÈS F. & REMANE J. (1971) - Standardcalpionellid zonation (Upper Tithonian-Valanginian) of the westernMediterranean province. Proc. II Plankt. Conference, 1337-1340.Roma.

AVELLONE G., BARCHI M., CATALANO R., GASPARO MORTICELLI M. &SULLI A. (2010) - Interference between shallow and deep-seatedstructures in the Sicilian fold and thrust belt. Journal of the Geological Society, London, 167, 109-126.

BASILONE L. (2007) - Mesozoic tectono-sedimentary evolution of theRocca Busambra (western Sicily). FIST - Geoitalia 2007, SestoForum Italiano di Scienze della Terra, 12-14 Settembre 2007,Rimini, Epitome, 2, 403.

BASILONE L. (2009) - Mesozoic tectono-sedimentary evolution of Rocca Busambra in western Sicily. Facies, 55 (1), 115-135.

BASILONE L., GASPARO MORTICELLI M. & LENA G. (2010) - Mesozoictectonics and volcanism from Tethyan rifted continental marginsin western Sicily. Sedimentary Geology, 226, 54-70.

BERNOULLI D. & JENKYNS H.C. (1974) - Alpine, Mediterranean andCentral Atlantic Mesozoic facies in relation to the early evolutionof the Tethys. Modern and ancient geosynclinal sedimentation. In:DOTT R.H. & SHAVER R.H. (Eds.). SEPM Spec. Publ., 19, 129-160.

BERTOK C. & MARTIRE L. (2009) - Sedimentation, fracturing and sliding on a pelagic plateau margin: the Middle Jurassic to LowerCretaceous succession of Rocca Busambra (Western Sicily, Italy).Sedimentology, 56 (4), 1016-1040.

BIOLZI M. (1985) - The Oligocene/Miocene boundary in selected Atlantic, Mediterranean and Paratethyan sections based on bio -stratigraphic and stable isotope evidence. Mem. Sci. Geol., 37,303-372.

BUTLER R.W.H. & GRASSO M. (1993) - Tectonic controls on base-levelvariations and depositional sequences within thrust-top and foredeep basins: examples from the Neogene thrust belt of centralSi cily. Basin Research, 5, 137-151.

CARON M. (1985) - Cretaceous planktic foraminifers. In: BOLLI H.M.,SAUNDERS J.B. & PERCH-NIELSEN K. (Eds.). Plankton Stratigra-phy, Cambridge Univ. Preess, 1, 17-86.

CATALANO R. & D’ARGENIO B. (1978) - An essay of palinspastic restora-tion across the western Sicily. Geol. Rom., 17, 145-159, Roma.

CATALANO R. & D’ARGENIO B. (1982a) - Schema geologico della Sici -lia occidentale. In: R. CATALANO & B. D’ARGENIO (Ed.). Guida

alla geologia della Sicilia occidentale. Guide geologiche regio -nali, Mem. Soc. Geol. It., suppl. A 24, 9-41, Palermo.

CATALANO R. & D’ARGENIO B. (1982b) - Infraliassic strike-slip tecto -nics in Sicily and Southern Apennines. Rend. Soc. Geol. It., 5, 5-10.

CATALANO R. & D’ARGENIO B. (Eds.) (1990) - Hammering a Seismic Section. Field trip in Western Sicily, Guide Book. Dipartimento diGeologia e Geodesia, Univ. di Palermo, pp. 19-22. May 17-19, 1990.

CATALANO R. & MONTANARI L. (1979) - Geologia dei Monti di Trabia-Termini Imerese e dei Monti Sicani orientali (Fogli Bagheria e Ter-mini Imerese, Sicilia centro-settentrionale). Rend. Soc. Nat. inNapoli, serie IV, 46, 1-27.

CATALANO R., AVELLONE G., BASILONE L. & SULLI A. (2010a) - NoteIllustrative della Carta Geologica d’Italia alla scala 1:50.000, foglio607 «Corleone». Regione Siciliana - ISPRA, SystemCart, 190 pp.

CATALANO R., AVELLONE G., BASILONE L. & SULLI A. (2010b) - NoteIllustrative della Carta Geologica d’Italia alla scala 1:50.000, foglio608 «Caccamo». Regione Siciliana - ISPRA, SystemCart, 224 pp.

CATALANO R., D’ARGENIO B., MONTANARI L., RENDA P., ABATE B.,MONTELEONE S., MACALUSO T., PIPITONE G., DI STEFANO E.,LO CICERO G., DI STEFANO P. & AGNESI V. (1978) - Contributialla conoscenza della struttura della Sicilia occidentale. Il profiloPalermo-Sciacca. Mem. Soc. Geol. It., 19, 485-493, Roma.

CATALANO R., DI STEFANO P., SULLI A. & VITALE F.P. (1996) - Paleo-geography and structure of the Central Mediterranean: Sicily andits offshore area. Tectonophysics, 260, 291-323.

CATALANO R., FRANCHINO A., MERLINI S., SULLI A., AGATE M. &BASILONE L. (1998) - Materiali per la comprensione dell’Assetto Pro-fondo della Sicilia Centro-Occidentale. In: CATALANO R. & LO CI-CERO G. (Eds.). Guida alle escursioni, La Sicilia occidentale, 79° Congresso della Società Geologica Italiana, Palermo, I,175-185.

CATALANO R., FRANCHINO A., MERLINI S. & SULLI A. (2000) - Centralwestern Sicily structural setting interpreted from seismic reflectionprofiles.Mem. Soc. Geol. It., 55, 5-16.

CATALANO R., SULLI A., ABATE B., AGATE M., AVELLONE G. &BASILONE L. (2004) - The crust in Western and Central EasternSicily. Field Trip Guide Book P45. 32° International GeologicalCongress, Firenze.

CHANNELL J.E.T., OLDOW J., CATALANO R. & D’ARGENIO B. (1990) -Palaeomagnetically Determined Rotations in the Western SicilianFold and Thrust Belt. Tectonics, 9 (4), 641-660.

CHRIST H.A. (1960) - Beitrage zur Stratigraphie and Palaontologie desMalm von West Sizilien. Schweiz. Palaeont. Abh., 77, 1-141, Basel.

DI MAGGIO C., AGATE M., CONTINO A., BASILONE L. & CATALANO R.(2009) - I depositi quaternari nei fogli CARG della Sicilia nord occi-dentale: implicazioni climatiche, ambientali e tettoniche. Il Quater-nario (Italian Journal of Quaternary Sciences), 22 (2), 347-366.

DI STEFANO E. & CATALANO R. (1978) - Biostratigraphy, palaeoecolo-gy and tectonosedimentary evolution of the preevaporitic depositsof the Ciminna basin (Sicilia). In: CATALANO R., RUGGIERI G. &SPROVIERI R. (Ed.). Messinian Evaporites in the Mediterranean,Mem. Soc. Geol. It., 16, 95-110.

DI STEFANO P. & MINDSZENTY A. (2000) - Fe-Mn encrusted «Ka-menitza» and associated features in the Jurassic of Monte Kumeta(Sicily): subaerial and/or submarine dissolution? Sedim. Geol.,132, 37-68.

FINETTI I.R., LENTINI F., CARBONE S., DEL BEN A., DI STEFANO A.,FORLIN E., GUARNIERI P., PIPAN M. & PRIZZON A. (2005) - Geo-logical outline of Sicily and Litospheric Tectono-Dynamics of itsTyrrenian Margin from new CROP Seismic Data. Crop Project:Deep Seismic Exploration of the Central Mediterranean andCentral Italy. Edited by I.R. FINETTI, 2005 Elsevier B.V.

FORESI L.M., BONOMO S., CARUSO A., DI STEFANO E., SALVATORINI G.& SPROVIERI R. (2001) - Calcareous plankton biostratigraphy ofthe Langhian-Serravallian Ras-Il Pellegrin section (Malta). In IAC-CARINO S. (Ed.). Integrated stratigraphy and paleoceanographyof the Mediterranean Middle Miocene. Riv. Ital. Paleont. Strat.,108 (2), 195-211.

FORNACIARI E., DI STEFANO A., RIO D. & NEGRI A. (1996) - MiddleMiocene quantitative calcareous nannofossil biostratigraphy inthe Mediterranean region. Micropaleontology, 42, 37-63.

GHISETTI F. & VEZZANI L. (1984) - Thin-skinned deformations of the Western Sicily thrust belt and relationships with crustal


shortening: mesostructural data on the Kumeta-Alcantara faultzone and related structures. Boll. Soc. Geol. It., 103, 129-157.

GIUNTA G. & LIGUORI V. (1975) - Considerazioni sul significato am -bientale e sul ruolo paleotettonico della Rocca Busambra (Sicilia).Boll. Soc. Nat. Napoli, 84, 45-49.

GULLO M. & VITALE F.P. (1986) - The «Megabreccia event» in the Upper Cretaceous-Eocene «Scaglia» of Western Sicily. Rend. Soc.Geol. Ital., 9, 195-202.

IACCARINO S. (1985) - Mediterranean Miocene and Pliocene planktonicforaminifers. In: BOLLI H.M., SAUNDERS J.B. & PERCH-NIELSEN K.(Eds.). Plankton Stratigraphy, 1, 283-314. Cambridge Univ. Press.

JENKYNS H.C. (1970a) - Growth and disintegration of a carbonateplatform. Neues Jb. Geol. Paläont. Mh., 6, 325-344.

JENKYNS H.C. (1970b) - Submarine volcanism and the Toarcian IronPisolites of Western Sicily. Ecl. Geol. Helv., 63 (2), 549-572.

JENKYNS H.C. (1971) - Speculations on the Genesis of Crinoidal Lime-stones in the Tethyan Jurassic. Geologischen Rundschau, 60 (2),471-488.

LENTINI F., CARBONE S. & CATALANO S. (1994) - Main structural domains of the Central Mediterranean Region and their Neogenetectonic evolution. Boll. Geof. Teor. e Appl., 36, 103-125.

MARTIRE L. & BERTOK C. (2002) - The Jurassic margin of a platformand its Cretaceous evolution. In: M. SANTANTONIO (Ed.), 6° In-ternational Simposium on the Jurassic System. General FieldTrip Guidebook. 19-22 settembre 2002, 156-164, Palermo.

MARTIRE L. & MONTAGNINO D. (2002) - A complex network of Juras-sic to Miocene Neptunian Dykes. In: SANTANTONIO M. (Ed.), 6th International Symposium on the Jurassic System. GeneralField Trip Guidebook, pp. 87-91, 19-22 September 2002, Palermo.

MARTIRE L., BERTOK C., PAVIA G. & SARTI C. (2002) - Stop 11 RoccaDrago: Mesozoic pelagic sedimentation over the faulted margin ofa pelagic platform. In: SANTANTONIO M. (Ed.), 6th InternationalSymposium on the Jurassic System. General Field Trip Guide-book, 91-96, 19-22 September 2002, Palermo.

MASCLE G. (1973) - Geologie sur la structure de Rocca Busambra(Sicile occidentale): mise en èvidence d’une tectonique antècèno-manienne. C.R. Acad. Sc. Paris, 276, 265-267.

MASCLE G. (1979) - Etude Géologique des Monts Sicani. Riv. It. Pa -leont. Strat., 16, 1-430, Milano.

MONACO C., MAZZOLI S. & TORTORICI L. (1996) - Active Thrust tec-tonics in western Sicily (southern Italy): the 1968 Belice earth-quake sequence. Terra Nova, 8, 372-381.

MONACO C., TORTORICI L. & CATALANO S. (2000) - Tectonic escape inthe Sicanian mountains (western Sicily). Mem. Soc. Geol. It., 55,17-25, 7ff.

NIGRO F. & RENDA P. (1999) - Evoluzione geologica ed assetto strutturaledella Sicilia centro-settentrionale. Boll. Soc. Geol. It., 118, 375-388.

NIGRO F. & RENDA P. (2001) - Oblique-slip thrusting in the Maghre-bide chain of Sicily. Boll. Soc. Geol. It., 120, 187-200.

OGNIBEN L. (1960) - Note illustrative dello schema geologico della Sicilia Nord-Orientale. Riv. Min. Sic., 64-65, 183-212, 2 tavv. disez. geol. 1:200.000. Palermo.

OLDOW J.S., CHANNEL J.E.T., CATALANO R. & D’ARGENIO B.(1990) - Contemporaneous Thrusting and Large-Scale rotationsin the Western Sicilian Fold and Thrust Belt. Tectonics, 9 (4),661-681.

PERCH-NIELSEN K. (1985) - Cenozoic calcareous nannofossils. In:BOLLI H.M., SANDERS J.B. & PERCH-NIELSEN K. (Eds.), Plank-ton Stratigraphy, 1, 427-554. Cambridge University Press.

ROURE F., HOWELL D.G., MULLER C. & MORETTI I. (1990) - LateCenozoic subduction complex of Sicily. Journ. of Structural Geology, 12 (2), 259-266.

RUGGIERI G. (1966) - Appunti sul Miocene della Sicilia occidentale.Riv. Min. Sic., 97-99, 18-24, Palermo.

SALVADOR A. (1994) - International Stratigraphic Guide. A guide tostratigraphic classification, terminology and procedure. The In -ternational Union of Geological Sciences and the Geological Society of America (Eds.), 214 pp.

SPROVIERI R., DI STEFANO E. & SPROVIERI M. (1996) - High resolu-tion chronology for Late Miocene Mediterranean stratigraphicevents. Riv. It. Paleont. Strat., 102, 77-104.

SPROVIERI R., BONOMO S., CARUSO A., DI STEFANO A., DI STEFANO E.,FORESI M.L., IACCARINO S.M., LIRER F., MAZZEI R. & SALVA-TORINI F. (2002) - An integrated calcareous plankton biostrati-graphic scheme and biochronology for the Mediterranean middleMiocene. Riv. It. Paleont. Strat., 108, 337-353.

STAMPFLY G.M. & BOREL G.D. (2002) - A plate tectonic model for thePalaeozoic and Mesozoic constrained by dynamic plate bounda -ries and restored synthetic oceanic isochrones. Earth and Plane-tary Science Letters, 169, 17-33.

TAMAJO E. (1960) - Microfacies mesozoiche della Montagna dellaBusambra. Riv. Min. Sic., 63, 131-151, Palermo.

VITALE F.P. (1996) - Sezioni geologiche attraverso i Monti Sicani cen-tro-occidentali. Dipart. di Geol. e Geod. La Tipolitografica s.n.c.,Palermo 1996.

VITALE F.P. & GIAMBRONE C. (1995) - Sovrascorrimenti di tipo duplex nei Monti Sicani: l’esempio di Castronuovo (Sicilia centrooccidentale). Natural. Sicil., S. IV, 16 (1-2), 39-62. Palermo.

WENDT J. (1963-1964) - Stratigraphisch-palaeontologische Untersu -chun gen im Dogger Westsizilien. Boll. Soc. Geol. Paleont. It., 2,57-145.

WENDT J. (1965) - Synsedimentare Bruchtektonik im Jura West-sizilien. Neus Jb. Geol. Paleont. Mh., 5, 286-311.

WENDT J. (1969) - Die stratigraphisch-paleographische Entwiklung desJura im Westsizilien. Geol. Rdsch., 58, 735-755.

WENDT J. (1971) - Genese and fauna submariner sedimentaarer Spal-tenfullungen im Mediterranean Jura. Palaeontographica, A (136),122-192.

60 L. BASILONE

Manuscript received 15 March 2010; accepted 5 June 2010; editorial responsability and handling by W. Cavazza.

Documents

Geological Map of the Rocca Busambra-Corleone region (western Sicily, Italy): explanatory notes